Cooling system for hybrid vehicle

ABSTRACT

A cooling system for a hybrid vehicle in which power from an engine and a motor can be transmitted to driving wheels through a clutch and a transmission mechanism may include a heater core fluid-connected to the engine to heat the interior of the hybrid vehicle, using cooling water from the engine, and a heat exchanger which may be arranged in parallel with the heater core and fluid-connected to the engine to receive the cooling water from the engine together with the heater core, and through which ATF (Automatic Transmission Fluid) that has cooled the motor and the transmission mechanism exchanges heat with the cooling water from the engine.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application claims priority to Korean Patent Application Number 10-2010-0097845 filed Oct. 7, 2010, the entire contents of which application is incorporated herein for all purposes by this reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a cooling system for a hybrid vehicle, and more particularly, to a technology that cools a motor and a transmission in a hybrid vehicle that uses power from an engine and a motor as a driving force and does not use a torque converter of the related art in the power transmission path from the engine to the transmission.

2. Description of Related Art

Hybrid vehicles are designed to be driven by power from an internal combustion engine and power from an electric motor and require a cooling system to appropriately remove heat that is generated while the engine, the motor, and the transmission generate power and keep supplying the power to the driving wheels.

The hybrid vehicles can be equipped with various types of power trains, one of which is to make it possible to transmit power from an engine and power from a motor to the driving wheels through a mechanism similar to an automatic transmission of the related art, and another one is to implement a configuration (hereafter, referred to as ‘transmission mechanism’) without using a torque converter that generates a relatively large amount of heat and consumes a lot of energy from the configuration of an automatic transmission of the related art.

That is, as shown in FIG. 1, power from an engine 500 is transmitted to a transmission mechanism 504 through a clutch 502, transmission mechanism 504 can transmit even the power from a motor 506 disposed between clutch 502 and the transmission, and obviously, transmission mechanism 504 is composed of only components corresponding to a gear train, a friction element, and a hydraulic controller, without a torque converter, in the configuration of an automatic transmission of the related art.

For cooling in the hybrid vehicle equipped with the power trains described above, engine 500 is cooled by a water-cooling type using cooling water circulating in engine 500, as in the related art, in which the cooling water is circulated by a water pump 508 and cools engine 500 while passing through engine 500, the heat is used for heating the interior through a heater core 510, and some of the heat prevents a throttle body from freezing through an ETC (Electronic Throttle Control) device 512 and cools the cooling water through an engine radiator 514.

Meanwhile, motor 506 and transmission mechanism 504 are also required to be cooled, such that, in the related art, as described above, engine radiator 514 is equipped with an oil cooler 516 and ATF (Automatic Transmission Fluid) circulating through motor 506 and transmission 504 circulates through oil cooler 516, thereby implement cooling.

However, in the configuration described above, the temperature of the ATF is difficult to rapidly rise to the normal level in cold-start of a vehicle, in which a loss of power is large because the viscosity of the ATF is large, such that it is disadvantageous in fuel efficiency.

For reference, an electronic device radiator 522 and a water pump 524 for cooling an electric part 518 and an ISG 520 (Integrated Starter Generator) for operating motor 506 are shown at the right side in FIG. 1.

The information disclosed in this Background of the Invention section is only for enhancement of understanding of the general background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art already known to a person skilled in the art.

BRIEF SUMMARY

Various aspects of the present invention are directed to providing a cooling system for a hybrid vehicle that improves fuel efficiency with reduction of a frictional loss by rapidly increasing ATF to a normal level of temperature in cold start, and smoothly removes heat of a motor and a transmission mechanism while minimizing reduction in heating performance for the interior of a vehicle in normal traveling, in a hybrid vehicle in which power from an engine and a motor is transmitted to driving wheels through a clutch and the transmission mechanism.

A cooling system for a hybrid vehicle in which power from an engine and a motor can be transmitted to driving wheels through a clutch and a transmission mechanism, may include a heater core fluid-connected to the engine to heat the interior of the hybrid vehicle, using cooling water from the engine, and a heat exchanger which may be arranged in parallel with the heater core and fluid-connected to the engine to receive the cooling water from the engine together with the heater core, and through which ATF (Automatic Transmission Fluid) that may have cooled the motor and the transmission mechanism exchanges heat with the cooling water from the engine.

The heater core may be fluid-connected with the engine through a cooling water connection pipe, the heat exchanger may be connected to a diverging connection pipe that diverges from the cooling water connection pipe, and the diverging connection pipe may have a diameter smaller than cooling water connection pipe, wherein the diverging connection pipe may have a diameter smaller by approximately 20% to approximately 60% than the diameter of the cooling water connection pipe.

The cooling system may further include an engine radiator that cools the cooling water from the engine, a water pump that pumps up the cooling water to the engine, and a thermostat that switches a supply state of the cooling water to the engine radiator in accordance with a temperature of the cooling water.

The cooling system may include an ETC (Electronic Throttle Control) through which the cooling water passing through the heat exchanger may be selectively controlled to pass, wherein the ETC may be disposed in parallel with the heater core and in series with the heat exchanger on the diverging connection pipe.

According to the exemplary embodiments of the present invention, it is possible to improve fuel efficiency with reduction of a frictional loss by rapidly increasing ATF to a normal level of temperature in cold start, and smoothly remove heat of a motor and a transmission mechanism while minimizing reduction in heating performance for the interior of a vehicle in normal traveling, in a hybrid vehicle in which power from an engine and a motor is transmitted to driving wheels through a clutch and the transmission mechanism.

The methods and apparatuses of the present invention have other features and advantages which will be apparent from or are set forth in more detail in the accompanying drawings, which are incorporated herein, and the following Detailed Description, which together serve to explain certain principles of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a diagram illustrating a cooling system for a hybrid vehicle according to the related art.

FIG. 2 is a diagram illustrating a cooling system for a hybrid vehicle an exemplary embodiment of the present invention.

It should be understood that the appended drawings are not necessarily to scale, presenting a somewhat simplified representation of various features illustrative of the basic principles of the invention. The specific design features of the present invention as disclosed herein, including, for example, specific dimensions, orientations, locations, and shapes will be determined in part by the particular intended application and use environment.

In the figures, reference numbers refer to the same or equivalent parts of the present invention throughout the several figures of the drawing.

DETAILED DESCRIPTION

Reference will now be made in detail to various embodiments of the present invention(s), examples of which are illustrated in the accompanying drawings and described below. While the invention(s) will be described in conjunction with exemplary embodiments, it will be understood that present description is not intended to limit the invention(s) to those exemplary embodiments. On the contrary, the invention(s) is/are intended to cover not only the exemplary embodiments, but also various alternatives, modifications, equivalents and other embodiments, which may be included within the spirit and scope of the invention as defined by the appended claims.

It is assumed that the present invention relates to a hybrid vehicle in which power from an engine and a motor can be transmitted to the driving wheels through a clutch and a transmission mechanism. An exemplary embodiment of the present invention, as shown in FIG. 2, includes a heater core 3 that heats the interior, using the cooling water from engine 1 and a heat exchanger 9 that is arranged in parallel with heater core 3 to receives the cooling water from engine 1 together with heater core 3 through which ATF that has cooled motor 5 and transmission mechanism 7 exchanges heat with the cooling water from engine 1.

Transmission mechanism 7 is a configuration with a torque converter removed, in the configuration of an automatic transmission of the related art, as described above.

Heater core 3 is connected with engine 1 through a cooling water connection pipe 11, heat exchanger 9 is connected to a diverging connection pipe 13 that diverges from cooling water connection pipe 11, and diverging connection pipe 13 has a diameter smaller than cooling water connection pipe 11.

That is, the cooling water from engine 1 flows into heater core 3 and a relatively small amount of cooling water flows into heat exchanger 9 such that heating performance of heater core 3 is not largely decreased and the viscosity of ATF is rapidly reduced to the normal level by rapidly heating the ATF flowing through motor 5 and transmission mechanism 7 with heat exchanger 9 in cold start. Accordingly, an effect of improving fuel efficiency is achieved by reducing a frictional loss and heat generated by motor 5 and transmission mechanism 7 can be smoothly removed through heat exchanger 9 in a normal driving.

In this configuration, it is possible to smoothly cool the ATF that cools motor 5 and transmission mechanism 7 only with a relatively small amount of cooling water flowing through diverging connection pipe 13, which is because only motor 5 and transmission mechanism 7, which generate a relatively small amount of heat, are cooled, without a torque converter that generates a relatively large amount of heat and consumes a lot of energy in the power train of the related art.

That is, the present invention performs optimization such that reduction in heating performance of heater core 3 in the power train of a hybrid vehicle with a torque converter of the related art removed is minimized while rapid warming-up of motor 5 and transmission mechanism 7 in cold start and appropriate cooling performance in normal driving can be ensured.

Diverging connection pipe 13 may has a diameter smaller by 20 to 60% than the diameter of cooling water connection pipe 11.

FIG. 2 shows a configuration including an engine radiator 15 that cools the cooling water from engine 1, a water pump 17 that pumps up the cooling water, and a thermostat 19 that switches the supply state of the cooling water to engine radiator 15 in accordance with the temperature of the cooling water, in which an electronic device radiator 21 is separately disposed at a side engine radiator 15 to cool an electric part 23 and an ISG 25, which is required to operate motor 5, and a water pump 27 is separately disposed to pump up the cooling water from electronic device radiator 21 to ISG 25 and electric part 23.

Meanwhile, an ETC 29 through which the cooling water passing through heat exchanger 9 passes is further disposed in parallel with heater core 3 and in series with heat exchanger 9 to prevent a throttle body from freezing.

ETC 29 is also disposed in series with heat exchanger 9, such that a relatively small amount of cooling water supplied through diverging connection pipe 13 passes.

The foregoing descriptions of specific exemplary embodiments of the present invention have been presented for purposes of illustration and description. They are not intended to be exhaustive or to limit the invention to the precise forms disclosed, and obviously many modifications and variations are possible in light of the above teachings. The exemplary embodiments were chosen and described in order to explain certain principles of the invention and their practical application, to thereby enable others skilled in the art to make and utilize various exemplary embodiments of the present invention, as well as various alternatives and modifications thereof. It is intended that the scope of the invention be defined by the Claims appended hereto and their equivalents. 

1. A cooling system for a hybrid vehicle in which power from an engine and a motor can be transmitted to driving wheels through a clutch and a transmission mechanism, the cooling system comprising: a heater core fluid-connected to the engine to heat the interior of the hybrid vehicle, using cooling water from the engine; and a heat exchanger which is arranged in parallel with the heater core and fluid-connected to the engine to receive the cooling water from the engine together with the heater core, and through which ATF (Automatic Transmission Fluid) that has cooled the motor and the transmission mechanism exchanges heat with the cooling water from the engine.
 2. The cooling system as defined in claim 1, wherein: the heater core is fluid-connected with the engine through a cooling water connection pipe, the heat exchanger is connected to a diverging connection pipe that diverges from the cooling water connection pipe, and the diverging connection pipe has a diameter smaller than cooling water connection pipe.
 3. The cooling system as defined in claim 2, wherein the diverging connection pipe has a diameter smaller by approximately 20% to approximately 60% than the diameter of the cooling water connection pipe.
 4. The cooling system as defined in claim 2, further comprising: an engine radiator that cools the cooling water from the engine; a water pump that pumps up the cooling water to the engine; and a thermostat that switches a supply state of the cooling water to the engine radiator in accordance with a temperature of the cooling water.
 5. The cooling system as defined in claim 4, further comprising an ETC (Electronic Throttle Control) through which the cooling water passing through the heat exchanger is selectively controlled to pass, wherein the ETC is disposed in parallel with the heater core and in series with the heat exchanger on the diverging connection pipe.
 6. The cooling system as defined in claim 2, further comprising an ETC (Electronic Throttle Control) through which the cooling water passing through the heat exchanger is selectively controlled to pass, wherein the ETC is disposed in parallel with the heater core and in series with the heat exchanger on the diverging connection pipe. 